The present invention relates generally to torque power tools.
Power tools are known in the art. Every torque power tool has an action force and an equal and opposite reaction force. Both forces tend to turn around a turning axis. In a hydraulic torque tool, a torque multiplier, an electric multiplier or an air wrench, the action equals the reaction in opposite direction. As tightening fasteners are becoming a more precise art, accurate or at least even bolt loads is a requirement. However, this can not be accomplished with slugging wrenches or impact wrenches.
There are two methods of tightening a bolt. One method is torquing and the other method is tensioning. However, it was not possible to convert a tool from a hydraulic torque tool to a hydraulic tensioner. In the past, customers had to buy a separate tool to tension corresponding fasteners.
While torquing is the way of turning a nut down on the bolt to elongate it, it has a disadvantage that it applies torsion to the bolt or has the bolt turned along with the nut, which in turn requires a use of back-up wrench applied to the nut on the other side of the application. Torque can be applied to any existing bolt and nut. Tensioning, on the other hand, requires the bolt to stick out by at least its diameter over and about the nut, so that it can be pulled upwards by a tensioner. Bolt replacements and most of the time nut replacements are necessary to apply tensioners. As it is the trend in industry to get away from cumbersome and complicated hydraulic tensioners, yet also from torquing due to the torsion and side-load applied to the bolt, mechanical tensioning is becoming very popular.